JP2000220522A - Crankcase of inclined engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crankcase of an inclined engine which is excellent in assembling performance, attaching performance to a working machine, sealability between an upper case and a lower case. SOLUTION: An engine mount part 10 is unitedly arranged on a bottom of a crankcase body 1. Front and rear ends 10a, 10b of the engine mount part 10 are projected from front and rear edges of a lower portion of the crankcase body 1. Bolt holes 11 are formed on the front and rear edngs 10a, 10b of the engine mount part 10 for fixing an engine. A vertical surface of a crankshaft is inclined in a bilateral direction of the crankcase body 1. Then the crankcase body 1 is divided into an upper case 20 and a lower case 30 along an inclined surface rotated around the crankshaft without bringing about a boundary surface such as bilateral wall surfaces 6b. In such a case, the engine mount part 10 is so divided that at least the front and rear ends 10a, 10b are arranged on the side of the lower case 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crankcase for an inclined engine in which a cylinder head is integrally formed.

[0002]

2. Description of the Related Art Conventionally, various proposals have been made for a crankcase of an engine integrally formed with a cylinder head. For example, Japanese Unexamined Patent Publication No. 6-058198 describes that a first engine housing (upper case) having a cylinder bore and an integral cylinder head is compatible with a first surface provided at a lower end of the first engine housing. A second engine housing (lower case) having a second surface to be
And a technique in which a bearing of a crankshaft is disposed at an interface between the first surface and the second surface.

[0003] Such an engine crankcase integrally formed with a cylinder head does not require a head gasket, so that the manufacturing cost can be reduced. Further, since a head bolt is not required, an intake and exhaust port arrangement is provided. The degree of freedom in design is increased, and effects such as the fact that the cylinder bore shape is kept true and the oil consumption can be prevented from deteriorating can be obtained because the cylinder head is not bolted by the head bolt.

However, in the technique described in Japanese Patent Application Laid-Open No. 6-58198, the crankshaft bearing is provided at the interface between the first engine housing and the second engine housing. Processing must be performed by temporarily assembling the first engine housing and the second engine housing.
Therefore, such a crankcase may increase the number of working steps in assembling the engine, and may cause an increase in manufacturing cost.

[0005] Further, in the crankcase of the engine, a working machine or the like may be directly connected to the left and right side surfaces on which bearings and the like are provided. The presence of an interface between the second engine housing and the second engine housing is not preferable in terms of structure.

To cope with this, as shown in FIG. 6, a crankcase 20 of an engine in which a cylinder head is integrally formed.
0 is divided into an upper case 201 and a lower case 202 along a plane β inclined from the vertical surface of the crankshaft 203, and a technique has been put to practical use.

[0007] According to this technique, the crankcase 200 can be divided into the upper case 201 and the lower case 202 without any interface on the right and left side walls of the crankcase 200 where the bearings and the like are provided. Therefore, there is no need to temporarily assemble the upper case 201 and the lower case 202, and the workability of the working machine or the like to the crankcase 200 is improved. In a crankcase 200 of an engine integrally formed with a cylinder head of this type, processing in a combustion chamber and the like are performed by inserting a tool from a lower portion of an upper case 201.
By dividing the crankcase 200 along the inclined plane β, the opening of the upper case 201 can be opened near the cylinder bore, so that the processing inside the combustion chamber can be easily performed. In addition, according to the above technology, since the inclined surface β dividing the upper case 201 and the lower case 202 is a flat surface, good sealing performance can be obtained.

[0008]

However, in recent years,
To reduce the overall height of the engine, tilt engines are widely used. However, when trying to divide the crankcase of the cylinder engine integrated tilt engine into an upper case and a lower case along a single sloping surface that can be divided without having an interface on the left and right side walls of the crankcase, For example, as shown in FIG. 7, the engine mount 210 is connected to the engine mount 2 on the upper case 211 side.
10a and engine mount 210 on lower case 212 side
b. And the engine mount 21
When 0 is divided into the upper case 211 side and the lower case 212 side, a load is applied to the sealing surface between the upper case 211 and the lower case 212 depending on the installation location of the engine and the like, so that sufficient sealing performance may be obtained. It will be difficult.

As described above, in the crankcase of a tilted engine integrated with a cylinder head, interfaces are present on the left and right side walls of the crankcase in order to improve the assemblability of the engine and the assemblability to a working machine. If the crankcase is divided into an upper case and a lower case along a single diagonal surface that can be divided without causing the division, it is difficult to obtain sufficient sealing performance.

The present invention has been made in view of the above circumstances, and has a cylinder head integrated type which has a good assembling property, a good assembling property for a working machine, and a good sealing property between an upper case and a lower case. It is an object of the present invention to provide a crankcase for an inclined engine.

[0011]

According to the present invention, there is provided a crankcase for an inclined engine according to the present invention, wherein a cylinder head is formed integrally with a crankcase main body, and the crankcase main body is supported on a bottom portion of the crankcase main body. The front and rear ends of the engine mount protrude from the front and rear edges of the lower part of the crankcase body, and bolt holes for fixing the engine are formed in the front and rear ends of the engine mount. The crankcase of the tilted engine provided with the crankcase body, the vertical surface of the crankshaft of the engine is inclined in the left-right direction of the crankcase body, and then along the inclined surface rotated around the crankshaft. The upper case and the lower case can be used without any interface between the left and right side walls of the crankcase body. With split bets, at least prior to the engine mount the engine mount, the rear end is characterized by being divided into shapes that are disposed in the lower case side.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 is an exploded perspective view schematically showing a crankcase of a cylinder head-integrated tilt engine viewed from a diagonally front upper left side, and FIG. 2 is an exploded perspective view of the cylinder head-integrated tilt engine. FIG. 3 is an exploded perspective view schematically showing the crankcase viewed from the bottom side, FIG. 3 is a perspective view of the crankcase of the cylinder head integrated tilt engine along the cylinder tilt direction, and FIG.
FIG. 5 is a bottom view showing the engine mount on the lower case side.

In FIG. 4, reference numeral 1 denotes a crankcase body of a tilt engine. A cylinder head 3 is formed integrally with an upper portion of the cylinder bore 2 of the crankcase body 1.

The lower end of the cylinder bore 2 faces the inside of the crank chamber 6, and a cylinder liner 5 is fitted into the inner periphery of the cylinder bore 2.

The cylinder head 3 has an intake port (not shown), a plug hole (not shown), an exhaust port 4 and the like.

In the crankcase body 1, crankshaft bearings 8 a, 8 b supporting a crankshaft 7 are provided on left and right side walls 6 a, 6 b constituting a crankcase 6.
(See FIG. 3). Note that reference numeral 9 in FIG.
Is a bearing that supports an intermediate gear shaft (not shown).

The crankcase body 1 is supported by a rectangular engine mount 10 integrally formed on the bottom of the crankcase body 1 with the cylinder bore 2 inclined around the crankshaft 7.

The front end 10 of the engine mount 10
a protrudes from the front edge of the lower part of the crankcase body 1,
The protruding front end portion 10a is provided with bolt holes 11, 11 near both right and left ends. The rear end 10b of the engine mount 10 is connected to the crankcase main body 1.
The lower rear edge protrudes from the lower rear edge 10.
The bolt holes 11 and 11 are provided in b at right and left ends. That is, in the four corners of the engine mount 10, bolt holes 1 for bolting the engine to a work machine are provided.
1 is provided.

Incidentally, such a crankcase of a cylinder head integrated type inclined engine is formed by being divided into two parts at the time of casting, and these parts are integrally connected.

More specifically, as shown in FIG. 3, the crankcase main body 1 is rotated around the crankshaft 7 after the vertical surface of the crankshaft 7 is inclined in the left-right direction of the crankcase main body 1. The upper case 20 and the lower case 30 are divided along the inclined surface α.

Here, the crankcase main body 1 is divided along the inclined surface α, so that the crankcase main body 1 is divided into the upper case 20 and the lower case 30 without any interface between the left and right side walls 6a and 6b of the crank chamber 6. Is done. That is, when the crankcase body 1 is divided by the inclined surface α, one of the left and right side walls 6a and 6b is disposed on the upper case 20 side, and the other is disposed on the lower case 30 side. In the present embodiment, the left wall 6
a is disposed in the upper case 20, and the right side wall 6 b is disposed in the lower case 30.

The engine mount 10 integrally formed on the bottom of the crankcase body 1 is divided along the inclined surface α into an engine mount 21 on the upper case 20 side and an engine mount 31 on the lower case 30 side. However, as shown in FIG. 5, the front end 10a of the engine mount 10 is formed integrally with the lower case 30 without being divided along the inclined surface α. That is, the bolt holes 11 provided at the four corners of the engine mount 10
All are arranged on the lower case 30 side.

The upper case 20 and the lower case 30 are provided with flanges 22 and 32 along the interface along the inclined surface α, respectively.
32 are provided with bolt holes (not shown) in the main parts.

The upper case 20 and the lower case 30 configured as described above are joined by joining the flanges 22, 32 via a gasket and fastening them with bolts when assembling the engine.

According to such a crankcase of an inclined engine integrated with a cylinder head, a head gasket is not required, so that the manufacturing cost can be reduced. Further, since no head bolt is required, the degree of freedom in designing the arrangement of the intake and exhaust ports is increased.

Further, since the cylinder head is not bolted by the head bolt, the cylinder bore shape can be maintained in a perfect circle to prevent deterioration of oil consumption.

Further, by dividing the crankcase body 1 into an upper case 20 and a lower case 30 along the inclined surface α, an interface exists between the left and right side walls 6a and 6b on which the crankshaft bearings 8a and 8b are arranged. The crankcase body 1 can be divided without causing the crankcase body 1 to be divided. Therefore, when processing the crankshaft bearings 8a and 8b and the like, it is not necessary to perform a temporary assembly of the upper case 20 and the lower case 30, and the working process at the time of assembling the engine can be simplified. In addition, since there is no interface between the upper case 20 and the lower case 30 on the left and right side walls 6a and 6b, it is possible to improve the assemblability when the working machine or the like is directly assembled to the crankcase body 1.

Further, by dividing the crankcase main body 1 along the inclined surface α, the opening of the upper case 20 (lower case 30) is formed near the lower end of the cylinder bore 2.
(An interface with the substrate) can be opened, and processing in the combustion chamber or the like can be easily performed.

Also, the upper case 20 and the lower case 3
0, the sealing surface surrounding the crankcase 6 is along the inclined surface α, so that the sealing surface can be formed on a single plane, the sealing structure can be simplified, and the sealing performance can be improved. Can be improved.

Further, the front and rear ends 10a and 10b of the engine mount 10 are projected from the front and rear edges of the crankcase main body 1 so as to be provided on the sealing surface of the crank chamber 6 between the upper case 20 and the lower case 30. By arranging the bolt holes 11 at the protruding front and rear ends 10a and 10b, the bolts at the four corners are maintained in a state where the sealing surface is maintained in a single plane. All the holes 11 can be arranged on the lower case 30 side. That is,
The front and rear ends 10a and 10b of the engine mount 10 in which the bolt holes 11 are provided project from the front and rear edges of the crankcase body 1, so that when the crankcase is divided, the inclined surface α However, even if the engine mount 10 is divided and all the bolt holes 11 are disposed on the lower case 30 side, the upper case 20 and the lower case 3
The sealing surface with zero can be maintained in a single plane. Therefore, even when the engine is bolted to the workbench or the like via the bolt hole 11, the upper case 20 and the lower case 3
Since no force in the interface direction is applied to the sealing surface between 0 and 0, the sealing performance can be maintained at a high level.

[0031]

As described above, according to the present invention, a cylinder head integrated type having a good assembling property, a good assembling property of a working machine, and a good sealing property between an upper case and a lower case. Can be provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view schematically showing a crankcase of a cylinder head-integrated tilt engine, as viewed from obliquely front left and above.

FIG. 2 is an exploded perspective view schematically showing the crankcase of the cylinder head-integrated tilt engine when viewed from the bottom side.

FIG. 3 is a perspective view of the crankcase of the cylinder head-integrated tilt engine along the cylinder tilt direction.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a bottom view showing the engine mount on the lower case side.

FIG. 6 is a front view of a crankcase of a conventional cylinder head-integrated engine.

FIG. 7 is a bottom view showing an example of an engine mount when a crankcase of a conventional cylinder head integrated type inclined engine is divided and formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Crankcase main body 3 ... Cylinder head part 6a ... Left side wall 6b ... Right side wall 7 ... Crankshaft 10 ... Engine mount part 10a ... Front end part 10b ... Rear end part 11 ... Bolt hole 20 ... Upper case 30 ... Lower case

Claims (1)

[Claims] 1. A cylinder head is integrally formed with a crankcase main body, and an engine mount for supporting the crankcase main body is formed integrally with a bottom portion of the crankcase main body, and front and rear ends of the engine mount are formed in the crankcase. A crankcase for an inclined engine, wherein the crankcase body is provided with bolt holes for fixing an engine at the front and rear ends of the engine mount, the crankcase body protruding from front and rear edges of a lower portion of the body. After tilting the vertical surface of the shaft in the left-right direction of the crankcase main body, along the inclined surface rotated around the crankshaft, the upper case and the lower case are provided without an interface on the left and right side walls of the crankcase main body. And mount the engine mount at least DOO before, crankcase inclined engine rear end is characterized by being divided into shapes that are disposed in the lower case side.